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P. I. GAGNON, 1R. AUTOMATIC FEED REGULATOR FOR MACHINES HAVING AIR SEPARATORS APPLICATION FILED SEPT.24, 1921.

I ELQQLSQgg Patented June 27 1922.

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m. GAGNON, JR. AUTOMATIC FE ED REGULATGR FOR MACHINES HAVING AIR SEPARATORS. APPLICATION FILED SEPT. 24, I921.

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tlNE'E'EfiQSTATE FATE ."PETER J. GAG-NON, F LOWELL, MASSACHUSETTS, ASSIGNOR OF ONE-THIRD TO J'. L. HENDERSON AND ONE-THIRD TO ALBERT GAG-N ON, BOTH OF LOWELL, MASSA- AUTOMATIC FEED REGULATOR FOR MACHINES HAVING AIR SIEEARATORS.

Specification of Letters Patent. Patented June 27 1922 Application filed September 24, 1921. Serial No. 503,037.

To all whom it may concern:

Be it known that I, PETER J. GAGNON, J r., a citizen of the United States, and resident of Lowell, county of Middlesex, State of Massachusetts, have invented an Improvement in Automatic Feed Regulators for Machines Having Air Separators, of which the following description, in connection with the accompanying drawing, is a. specification,

10 like characters on the drawing representing regulating the feeding means.

In certain types of grinding mills, 'such,

4 for example, as the well known Raymond type of mill, the material is fed by a rotatable feeder into the grinding chamber whereit is finely ground or pulverized by a rotating centrifugal roller, or by' beaters, or otherwise, andthe finished material is removed from the mill by a suction current passing through an air separator forming a part of or communicating with the, grinding chamber. In such machines the feeding of an excess amountof material to the grinding mill causes amore or less stoppage of the ports through which the air enters the mill and thereby diminishes the air pressure within the separator and adversely af fects the proper operation of the air separator. It not-only affects the efliciency of the mill, but varies the character of the product delivered from-the mill, In grindin mills of this character means have here-.

tofore been provided for regulating the feeding mechanism, but such means have been under manual control, thus requiring the attendance of an operator to each mill, or battery of mills. The object of the present in- -vention is to provide automatically operable means responsive to variations in pressure of the air in the air separator to control the regulating means for the feeding -mecha- I11SI1'1.

More specifically the invention relates to grinding machines having rotatable feeding mechanism operable by one or more ratchets and co-operatingreciprocating pawls havng electrically operated means for renderlng the active pawlinoperative, said electrically operated means being controlled by a pneumatically actuated device which is responsive to variations of the pressure of the air in the air separator. l

A further object of the invention is to provide a regulating means of the character described which can be applied readily to machines of usual types.

A preferred embodiment of the invention is illustrated herein as applied to a grinding mill of the Raymond type which is I provided with an air separator for removing and delivering the finely ground material, but it will be understood that the invention may be applied to any type of grinding machine, or to an air separator having suitable feeding means for the materlal to be separated, within the spirit and scope of the claims.

In the drawings: Fig. 1 is a perspective View of a well known form of the Raymond type of mill to which my invention is applied; Fig. 2 is an elevation of a sufiicient portion of the mill illustrated in Fig. 1 to show the application of my invention thereto;.

Fig. 3 is a detail view of one of the ratchets for actuating'the feeding mechanism,' illustrating the co-operating pawl and themeans for reciprocating-the same and the connection by which the pawl is removed from the ratchet and rendered inoperative. Figure 4:, is a detail view of the mill used in connection with the feeder of any invention, the casing being partly broken away. The mill illustrated in the accompanying drawings is a centrifugal mill of thewell known Raymond type provided with an air separator and a collector for the finished material. This general type of grinding mill, forms of which are illustrated in Pat= entNo. 897 ,400 granted to A. Raymond,

September 1, 1908, comprises a grinding chamber having a horizontal grinding ring with which a plurality of centrifugal rolls co-operate. The centrifugal rolls are carried by substantially vertical shafts which are pivoted -near their upper ends upon a spider which is fixedly secured upon a vertical central driving shaft. The grinding ring and rotating rolls are located at a short distance above the bottom of the grinding chamber and the material which is fed into the mill drops into the grinding, chamber and is thrown upwardly into the paths of the rolls by plows which are carried by a sleeve shaft connected to the spider which. actuates the centrifugal rolls.

The material is fed into the grinding chamber by a pocketed rotatable cylinder.

The air separating chamber in this particular type of mill is located above and forms a continuation of the grinding chamber. A suitable blower draws the air from the separating chamber and delivers the same, together with the material carried by the current of air, into a collector as will hereinafter he more fplly described. i

The air is introduced into the mill through a series of tangential ports communicating with the grinding chamber below the grinding mill. If, during the operation of the machine, an excessive amount of material is fed into the grinding chamber the tangential admission portsbecome more or less filled up and clogged, thereby shutting off the free entrance of air into the mill and, consequently, diminishing the air pressure within the air separator. This seriously i modifies the action of the separator and also interferes with the proper functioning of the mill.

Means which have heretofore been provided for manually controlling the regulation of the feeding mechanisms will hereinafter be more fully described.

Inasmuch as the general construction of the mill above described is well known, detail illustration thereof has been omitted and only the external configuration-of the mill shown in thedrawing.

a The grinding chamber, (not shown), is

supported upon the base 1, and the grinding mechanism is driven by a main shaft 2 which is actuated through a suitable driving pulley 3. The air separator 4 is of substantially cylindrical form and communicates at its lower end with the grinding chamber. The upper portion of the air separator, as illustrated, comprises reversely arranged conoidal sections 5 and 6, the upper of which is provided with a central pipe 7 which leads to an outlet pipe 8 communicating with the eye of a blower fan 9which discharges its current into a well known cyclone type of collector 10 having a downwardly extending conicol barrel 11 provided at its bottom with .with its co-operating ratchet.

13, leading from the upper central portion of the cyclone collector, communicates with a vertical pipe 1 1 which is connected to a casing 15 which surrounds the lower portion of the grinding chamber and delivers air into the lower portion of the grinding chamber through the tangential ports above described. The pipe or conduit 13 is illustrated as communicating with a pipe 16 which may lead to an auxiliary separator or duslt collector as is common in this type of mil.

The'material is fed to the mill through a chute 17 which communicates with a casing 18 having therein a pocketed rotating cylinder 19 mounted upon a shaft 20, the rotation of the pocketed cylinder delivering measured quantities of material to the grinding chamber dependent upon its speed of rotation. The shaft 20, as illustrated herein,

is provided with a plurality of ratchets 21', i

In the present illustra shaft 29 which is carried by rocker arms 30 y and 31 which are pivotally mounted upon the shaft 20. One of the rocker arms 31 is connected by a link 32 to a stud 33 which is adjustably mounted in a slot 34: in a crank 35 which is fixedly secured upon a countershaft 36. The counter-shaft 36 is journallecl in a suitable bracket 37 and is provided with a pulley 38 which is driven. by a belt 39 from a pulley -10 upon the main driving shaft 2.

The grinding mill, its feeding mechanism and the air separating mechanism above described are all of the usual construction.

The rate of the feeding of the material to the grinding mill is controlled by selectively placing one of the pawls into engagement Inasmuch as the field of reciprocation of the pawls is uniform, but the diameter of the ratchets vary, the speed of rotation of theocketed feed cylinder may be varied by se ectively changing the pawl which engages a co-operating ratchet. Heretofore regulation of this type of feeding mechanism has been performed by hand. The present invention contemplates the provision of automatic means responsive to the variation of air pressure in the air separator to regulate the speed of rotation of the feeding mechanism. This is accomplished by providing means the air pressure within the air separator beyond a predetermined amount, to remove the pawl from engagement with its ratchet and thereby render the feeding mechanism inoperative until the air pressure in the air separator is restoredto the predetermined amount, whereupon the pawl will again be automatically engaged with its ratchet and the feeding operation resumed.

Any suitable means responsive to variation of the air pressure in the air separator may be employed thus to control the actuation of the feeding mechanism. In the preferred' embodiment of the invention pneumatic means connected to the air separator is provided which controls an electric circuit leading to a solenoid, the core of which is adapted'to be connected to any of the pawls end of a link 41 which is connected at its upper end tothe core 42 of a solenoid 43' which may be supported in any suitable manner. For purposes of clearness of illustration the solenoid and its connection to the pawls are greatly exaggerated as is also the pneumatic mechanism which controls the action of the solenoid. The solenoid is energized by a suitable electric current, which may be of one hundred and ten volts or more or less, supplied from a suitable generator (not shown) through a conductor.44 leading to the solenoid and the return conductor 45. The conductor 45 is provided with a switch comprising terminals 46 and 47 which are adapted to be connected by a switch arm 48 which is pivotally mounted .on a suitable supporting stud 49 and is pro vided with an extension 50 to which a spring 51 is attached which normally holds the switch arm out of engagement with the terminals 46 and 47 A suitable pin 52 may be provided to limit the movement of the switch arm 48. I

The switch arm 48 desirably forms the armature of a relay electromagnet 53 which is adapted to be energized by a small current of relatively low voltage which may be supplied by a-battery through a conductor 54 leading to themagnets 53 and returning through a conductor 55. The conductor 55 is provided with a switch which is controlled by a pneumatic device which is responsive to the variations of air pressure in the separator.

As illustrated herein the pneumatlc controller comprises a chamber within a conoidal casing 56, the upper end of which is connected by a pipe'57 with the air separator. Thelower end of the casing 56 is provided with a diaphragm 58 to which is secured a rod 59 which is slidably mounted in a suitable bracket 60. The conductor 55 is connected to the bracket 60 which forms one of the terminals of the switch. An arm 61 secured upon the rod 59 forms the movable switch member and is adapted to be moved into or out of contact with the other terminal 62 of the conductor 55. During the normal operation of the mill, when the air pressure in the air separator is not unduly diminished by the suction of the fan, the diaphragm 58 remains in substantially horizontal position and the switch member 61 is out of contact with the terminal 62.-

The relay, therefore, is not energized and its armature remains in the position illustrated in fiill lines in Fig. 2. When in this position the circuit leading to the solenoid 43 is broken'and the solenoid core is drawn down by gravity so that the pawl, to which the solenoid is connected by the link '41, is in engagement with its ratchet. VYhen, however, the air pressure in the air separator issufiiciently diminished a-partial vacuum is created in the chamber within the conical casing 56 which raises the diaphragm 58 into the position illustrated in dotted lines in Fig. 2, thus causing the switch contact 61 to engage the terminal 62, thereby completing the circuit through the relay magnet 53. The relay magnet thus energized attracts the armature 58 and draws the same into the of the feeding mechanism. Thus the active pawl is rendered inoperative and feeding of the material. is caused to cease. When continued operation of the grinding mechanism and the blower has removed a suflicient amount of the material which had accumulated in the lower portion of the grinding chamber and had obstructed the free entrance of air into the grinding chamber the pressure of the air within the air separator will have been restored thereby decreasing the amount of vacuum in the chamber above the diaphragm 58 and permitting the dia phragm to be restored to its original position. The rod 59 will thereupon descend by gravity and break the contact of the arm 61 with the terminal 62, thus de-energizing the relay magnet 53 and permitting its armature 48 to fall, thereby breaking the circuit to the solenoid and permitting the core 42 to drop so that the active pawl again engages and operates its ratchet to resume the" feeding operation.

It will be observed that the pneumatically actuated controlling mechanism and the electrically operated regulating mechanism for the feeding device are graphically illustrated herein and it is intended that this graphic illustration shall include any suitable device of the character described for controlling andregulating the feeding mechanism. It may also be mentioned that a. suitable pneumatically actuated mechanism may be employed directly to control the feeding mechanism without the interposition of electrical regulating means, said electrical regulating means being suggested for the purpose of providing a more sensitive regulation. The relay mechanismnlay if desired be eliminated for it is employed mainly for the purpose of preventing arcing of the switch in the circuit leading to the solenoid and also for the purpose of rendering the action of the controlling mechanism more sensitive. It will, therefore, be understood that the embodiment of the invention illustrated and particularly described herein is of an illustrative character and is not restrictive, and that various changes in construction, arrangement and operation may be made within the spirit and scope of the following claims.

2-.In a machine of the class described comprising grinding means, means for feeding the material to be ground to said .grindlng means, a separating chamber and means for creating a suction of air through said separating chamber to remove the finely ground material therefrom, and means for regulating said feeding means operable by variations of the partial vacuum in said separating chamber.

3. In a machine of the class described comprising feeding means, a separating chamber and means for creating a suction of air through said separating chamber to remove the finely ground material therefrom, means forarresting the, feeding of the material to said machine operable by the diminution ofthe air pressure in said air 7 chamber.

4. In a machine of the class described comprising feeding means, a separating chamber .and meansfor creating a suction of air through said separating chamber to remove the finely ground material there- 3 from, a pneumatic chamber communicating with said separating chamber, a member re ciprocable by variations of air pressure in said pneu'maticchamber and means operable by the reciprocation of said member to regulate said feeding means.

5. In a machine of the class described comprising rotatable feeding means, means including a ratchet anda reciprocating pawl for rotating said feeding means, and an air separator for removing the finished material, means operable by diminution of the air pressure in said air separator to render said pawl inoperative.

6. In a machine of the class described comprising grinding means, rotatable feeding means for supplying the material to be ground to said grinding means, means including a plurality of ratchets of different diameter and co-operating reciprocating pawls selectively operable to actuate said ratchets and thereby to impart different speeds of rotation to' said feeding means and an air separator for removing the finely ground material, regulating means adapted to be connected to either of said pawls and means operable by the diminution of the air pressure in said air separator to render the active pawl inoperative.

7-'In a machine of the class described comprising feeding means and an air separator for removing the finished material,-

electrically actuated means for regulating said feeding means and pneumatically operated means responsive to the air pressure in said air separator for controlling said electrically actuated regulating means.

8. In a machine of the class described comprising rotatable feeding means, means including a ratchet and a reciprocating pawl for rotating said feedingmeans and an air separator for removing the finished material, electrically actuated means for rendering the action of said pawl ineffective and means .operable by the diminution of the air pressure in said ia'ir separator to control said electrically actuated regulating means.

9. In a machine of the class described comprising grinding means, rotatable feeding means for supplying the material to be ground to said grinding means, means including a ratchet and a co-operating pawl for rotating said feeding means and an air separator for'removing the finely ground material, a solenoid having a core connected to said pawl, a circuit for supplying an elec tric current to said solenoid, a switch in said circuit and pneumatically operated means responsive to the diminution of the air pressure in said air separator to close said switch thereby energizing said solenoid and causing the same to remove saidpawl from said ratchet and render the feeding mechanism inoperative.

10. In a machine of the class described comprising grinding means, rotatable feeding means for supplying the material to be I ground to said grinding means, means including a ratchet and a co-operating pawl Y for rotating said feeding means and an air separator for removing the finely ground niaterial, a solenoid having a core'tconnect'ed -to said pawl, aci rc u it for supplying an electric current to said solenoid, a switch in said circuit, an electrical relay for-ac'tuatingsaicl switch, and pneumatically operated means responsive-to the diminution of the air pres sure in said. a ir separator to actuate said relay tofelose said switch thereby energizing 10 said solenoidand causingthe same to remove saidpaw llfrom said-ratchet and render the 

